#include<stdio.h>
#include<string.h>
#include<unistd.h>
int main()
{
  printf("hello printf\n");
  fprintf(stdout,"hello fprintf\n");
  char*msg="hello fwrite\n";
  fwrite(msg,strlen(msg),1,stdout);
  
  char*ss="hello write\n";
  write(1,ss,strlen(ss));

  //./a.out > xx.txt
  return 0;
}
